This invention relates to a device for turning around filter tip cigarettes, which is designed for changing two side-by-side parallel rows of filter cigarettes, which are formed by a succession of parallel pairs of co-axial cigarettes with their filters in facing relation, into only one row of parallel cigarettes with their filters being oriented in the same direction, which device comprises two fluted, conical, preferably suction, turn around drums, of which one takes the cigarettes forming one of the two cigarette rows, and lays them in a turned around position, i.e., rotated by 180.degree. about a transverse axis thereof, between the cigarettes of the other cigarette row.
In the turn around devices of the type as above disclosed, which are, for example, known from the Italian Pat. No. 781,944, the ends of the not turned around cigarettes and the ends of the turned around cigarettes that are inserted between the not turned around cigarettes, are not into mutual alignment, but are offset in the longitudinal direction of the cigarettes, i.e., transversely to the single cigarette row, because the point of coincidence of the ideal vertices of the two turn around conical drums must be necessarily shifted with respect to the plane of substantial contact between the facing filters of the pairs of cigarettes forming the two cigarette rows, in order to avoid any interference between the cigarettes. Consequently, when using the known turn around devices of the above-disclosed type, special cigarette-aligning means must be provided for the cigarettes being oriented with their filters in the same direction and alternately belonging to the not turned around and to the turned around row of cigarettes, in order to form one single cigarette row. These cigarette-aligning means consist of small pistons which, for example, are fitted on a cigaratte-conveying fluted drum, or of a stationary frontal cam which, for example, is co-axial to a cigarette-conveying fluted drum. The cigarette-aligning pistons however are complicated in construction, and are also scarcely reliable since their movement may be disturbed by the tobacco dust. The cigarette-aligning cam instead, causes some difficulties at high speeds, also on account of the fact that the degree of the longitudinal displacement of the cigarettes to be aligned is quite important.
The object of the present invention is to eliminate the said drawbacks by having the cigarettes of the turned around cigarette row laid between the cigarettes of the not turned around cigarette row, with the ends of the turned around cigarettes being already aligned with the ends of the not turned around cigarettes.
To this end, according to the invention, between the point at which the cigarettes to be turned around are withdrawn, and the first conical turn around drum, and/or between the second conical turn around drum and the point in which the turned around cigarettes are laid, intermediate transfer means are interposed, of which at least one determines an axial displacement of the cigarettes, which is adapted for counterbalancing the axial displacement as determined by the conical turn around drums, whereby the turned around cigarettes are laid and positioned into alignment with the not turned around cigarettes.
Preferably, according to one embodiment of the invention, the intermediate transfer means that is associated to one of the conical turn around drums, for example the transfer means arranged between the point of withdrawal of the cigarettes to be turned around and the first conical turn around drum, is a fluted, conical, preferably suction, transfer drum, while the intermediate transfer means that is associated to the other conical turn around drum, for example the transfer means arranged between the second conical turn around drum and the point in which the turned around cigarettes are laid, is a fluted, cylindric, preferably suction, transfer drum. Of course, the intermediate transfer means arranged upstream and downstream of the two conical turn around drums, may be both fluted, conical, preferably suction, transfer drums.